The construction of a commercial building and/or residential home involves the installation of numerous doors and windows. In recent years, doors and windows are commonly designed as a single unit to facilitate the installation of such units. Conventionally, an exterior wall is constructed with an opening sized to receive the door and/or window unit and caulking is applied around the interface of the wall and/or jamb and the door and/or window unit to prevent moisture and/or water from entering into the interior of the building. Over a period of extended time the seal between the door and/or window unit and the exterior wall created by the caulking deteriorates due to exposure to environmental conditions thereby allowing water and/or moisture to enter into the interior space of the building.
The principal objective of the present invention is to provide a water proof barrier between a window and/or door unit and an exterior wall which will not deteriorate when exposed to adverse weather conditions. Another objective of the present invention is to provide a system which allows a window and/or door unit to be easily installed within an exterior wall while providing a water proof barrier which will not deteriorate when exposed to adverse weather conditions. Another objective of the present invention is to provide an air dam at the jams of the window and/or door jams in order to prevent the flow of air which may or may not carry moisture from the outside environment of the exterior wall system into the interior space of a building.